Protective ring for crusher locking nut



Nov. 20, 1962 PROTECTIVE RING FOR CRUSHER LOCKING NUT Filed Sept. 16, 1959 W. KOWALOWSKI 2 Sheets-Sheet l INVENTOR. WILL/AM KOWALOWSK/ ATTORNEYS Nov. 20, 1962 w. KOWALOWSKI 3,064,909

PROTECTIVE RING FOR CRUSHER LOCKING NUT Filed Sept. 16, 1959 2 SheetsSheet 2 INVENTOR.

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United States Patent M 3,064,909 PROTECTIVE RING FOR CRUSHER LOCKING NUT William Kowalowski, Silver Bay, Minn, assiguor to Reserve Mining Company, Silver Bay, Minn., a corporation of Minnesota Filed Sept. 16, 1959, Ser. No. 840,309

4 Claims. (Cl. 241-293) This invention relates to an improvement in rock crushers of the gyratory cone type. It is particularly concerned with novel and improved protective means for the locking nut which retains the mantle element or elements on the central shaft assembly.

The invention will be described in one useful adaptation comprising an ore crusher utilized in the breaking to a predetermined size of hard rock fragments, for example fragments of the low grade iron ore known as taconite.

The crushers which normally crush the mine-run rock fragments are preferably designed and controlled so that a predetermined output size is obtained. This output size is determined mainly by the relative positioning and spacing of the so-called concaves and mantles.

One type of common coarse crusher comprises a stationary shell having one or more of the aforesaid concaves rigidly fastened to the interior wall of the shell to define a fixed frusto-conical crushing surface.

A mantle, generally conically shaped in external configuration, is mounted on a shaft, the latter being disposed vertically and supported on its lower end such that the mantle extends upwardly within the shell. The mantle is spaced radially inwardly of the concaves to provide a downwardly converging annular space therebetween defining a crushing zone. The mantle-carrying shaft is normally gyratably driven from its lower end in such manner that the mantle alternately approaches and recedes from the concaves to a limited extent at any point, except at the center of gyration, and hence, as the particles of ore material fall into the crushing zone, the same are nipped and crushed.

The mantle may be assembled on the shaft (or on a sleeve member carried on the shaft) with a slight internal clearance to permit the use of a liner of zinc or other low melting point metal. Since the mantle is subjected to severe wear, and must periodically be replaced, it may be heated, with a torch or otherwise, to cause melting of the metal liner, and thereupon the worn mantle may be lifted upwardly from the head center.

The mantle is held in place by a large threaded nut which is rotatably advanced on a threaded upper end portion of the shaft until it contacts the top edge of the mantle shell. In the conventional type of crusher this locking nut, as it will hereinafter be termed, is almost directly in the path of rock fragment charging movement and in the past it has had to be frequently replaced. It is a large and heavy cast nut and machining such a nut is an expensive procedure.

It is an object of the present invention to provide easily replaceable protective means for a mantle locking nut for a gyratory crusher whereby to reduce the cost incident to wear on the nut,

Other objects and advantages will be apparent from a study of the following description of one embodiment of the invention, in conjunction with the accompanying drawings, in which:

FIG. 1 is a vertical sectional view, showing a crusher having a mantle locking nut embodying my invention.

FIG. 2 is an enlarged detail view of a portion of the crusher shown in FIG. 1.

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2.

3,064,999 Patented Nov. 20, 1962 Referring now to the drawings, the type of crusher shown is conventional, with the exception of the invention to be described. The crusher is housed in a shell 10 which serves as a main frame to support the working elements. The shell is carried on a base 11 which has an upwardly extending central sleeve 12 within which is a rotatable eccentrically bored bushing 13. Fixed to the bushing is a bevel ring gear 14 adapted to be rotated by a bevel pinion 15 fixed on a shaft 16. It is obvious that when the shaft 16 is driven from any suitable power source the bushing 13 will gyrate eccentrically around a fixed central axis represented by the axis of the bore in sleeve 12.

Within bushing 13 is a vertical crusher shaft 17. On the top of the shaft is a feed distributor 18 and a feed plate 19. The feed distributor rests on a locking collar 20 which in turn is attached to a crusher head 21 by studs 22.

The crusher head carries a mantle 23, there being a lining 24, usually of low melting point metal, between the head and the mantle; The mantle is retained in position by an annular locking nut 25 which is threaded on the bell-flared portion of the locking collar.

A bowl structure 28 is carried on the top of the shaft from which is suspended a concave or lining 29 by means of lugs 29a which hook over U-bolts 30 on the bowl.

It will now be understood that when drive shaft 16 is rotated the crusher shaft and mantle move in gyratory or rotary rocking fashion, pinching and crushing rock fragments which are discharged into the receiving hopper 31 and which fall into the varying clearance space between the mantle 23 and the concave 29.

In view of the fact that a crusher of the type above described is previously well known in the art, it is believed that the foregoing description of the crusher operation will be sufficient for an understanding of the invention now to be described.

It can be observed that when material is discharged downwardly into hopper 31, and takes the route shown by the arrows, the falling rock fragments strike with heavy, abrading impact on mantle locking nut 25, and under former conditions this nut had to be frequently replaced. I have provided a means which greatly lessens the necessity of such replacement by greatly reducing the wear on the nut.

Referring especially to the enlarged view of FIG. 2, the outer periphery of the nut 25 is shaped to conform to the inner contour of a protective ring 34 which in turn abuts the top edge of mantle 23. The nut has an outwardly projecting shoulder 25a which contacts the top edge of ring 34 so as to force the ring downwardly against the mantle in tight fitting contact when the nut is advanced by rotation in tightening direction on the shaft threads. It will be observed that the protective ring 34 is disposed just outwardly and in the horizontal zone occupied by the nut and shaft threads. The protective ring is considerably less expensive than .a locking nut, and since it occupies a large portion of the outer periphery of the nut it suffers most of the impacts and abrasion.

With an arrangement such as I propose a choice is available as to the respective alloy materials for the nut and for its protective ring. The ring may be made from relatively more abrasion resistant material of good casting properties while the nut may be formed from a more readily machineable alloy which need not necessarily be exceptionally abrasion resistant.

While I have described the invention with reference to its use as a protective means for a clamping nut for retaining a crusher mantle on its shaft, it will be obvious that it may be used in other adaptations of related nature.

What is claimed is:

1. In a crusher, a crushing assembly comprising a shaft, alcrusher head carried on said shaft, a crushing member mounted on said crushing head outwardly from said shaft, a sleeve member fixedly attached to said crusher head coaxially therewith and extending above the upper end of said shaft, said sleeve having external peripheral threads thereon, a two-piece nut assembly suitably threaded to be advanced downwardly on said peripheral threads, a peripheral surface portion of said nut assembly having a protective annular member covering a portion of its outer surface in registry with the transverse zone of the screw threads, said annular member being in retaining contact with an upper edge portion of said mantle.

2. Apparatus as defined in claim 1 wherein said nut has an outwardly projecting part in contact with the top of the protective annular member in mantle-retaining position.

3. In' a crusher a crushing assembly comprising a shaft, a crusher head carried by said shaft, a crushing member mountedon said crushinghead outwardly from said shaft, a sleeve member fixedly attached to said crusher head coaxially therewith and extending above the upper end of said shaft, said sleeve having external peripheral threads thereon, a two-piece nut assembly suitably threaded to be advanced downwardly on said peripheral threads, an outer peripheral portion of said nut assembly being undercut to provide a peripheral recess, said two-piece assembly including a protective ring of abrasion resistant material mounted in said recess, and rigidly gripped when said nut is advanced to mantleretaining position.

4. Apparatus as defined in claim 3 wherein said ring is positioned radially outwardly in the transverse zone of the screw threads.

References Cited in the file of this patent UNITED STATES PATENTS 2,070,270 Gruender Feb. 9, 1937 2,635,818 Zoerb Apr. 21, 1953 2,883,218 Roubal Apr. 21, 1959 FOREIGN PATENTS 305,398 Great Britain Feb. 7,. 1929 

